In the past, it has been known to produce portable seat cushions formed of a resilient material such as, for example, an elastic foam material especially configured, designed and adapted for placement upon seats found in both public and private outdoor entertainment venues. These venues, such as, for example, football stadiums, baseball stadiums, outdoor concert areas are often equipped with practical, but rather rigid seating. The rigid nature of such seats, often constructed of a hard plastic, wood or metal are not particularly comfortable to sit upon, especially during prolonged concerts, sporting events and other publically viewed activities. In order to relieve the pressure of sitting upon such hard surfaces, portable seat cushions have been manufactured, sold and utilized as a soft resilient layer intended to cover the seating surfaces upon which an individual is seated—especially the areas of the seat upon which the upper legs, buttocks and lower back are supported—.
It has been known to produce such outdoor seating cushions with sufficient resilient foam material to reduce painful pressure points at the above-mentioned anatomical sitting areas. These cushions are often enclosed in a water-proof plastic cover in order to provide a water-proof barrier. Many of the prior art cushions are light enough to be easily transported to a site of use and, due to the compression-friendly nature of the foam selected for their manufacture, are easily folded so as to simplify packing them within a bag or other carrier. Some seat cushions may also include a strap or other simple handle to further enhance portability.
Besides the rather uncomfortable rigid seating commonly found in public venues and transportation, temperatures, especially at outdoor arenas, amphitheaters and stadiums may often drop to uncomfortable levels. Although cold temperatures may not be a problem for short duration events with appropriately clothed individuals, events taking longer periods of time such as outdoor concerts and sporting events may often last many hours during which such cold temperatures may adversely effect spectators forced to sit in already uncomfortable rigid seats. It would be highly desirable if a seat cushion could be disclosed especially designed, shaped and configured to accept, contain and safely operate a heat source. It would be still further advantageous if such a portable cushion could be utilized with and without such a heat source, but retaining the ability to incorporate the heat source by simply adding a removable heat source from the especially configured cushion.